Two-wheel drive two-wheeled vehicle

Abstract

The present invention is a fully functioning two-wheel drive bicycle and embodiments thereof. The drive train which supplies power to the front wheel is incorporated into a modified frame and comprises a rear wheel driven by the traditional chain or shaft mechanism and the front wheel driven by a series of rigid shafts or other internalized drive systems. The front wheel drive is adaptable to all bicycle frame geometries including the double diamond mountain bike and road bicycle frame, touring, commuter and comfort bicycles, BMX, trials bicycles, and recumbent and tandem bicycles. The drive train lengthens and shortens in parallel with the shock-absorbing front fork and rear suspension. An engagement clutch, a one-way hub, and torque limiting clutch are also disclosed.

We claim:  
     
         1 . A two-wheel drive bicycle, comprising: 
 a frame, the frame including a head tube;    a power transfer mechanism;    a shock-absorbing rear suspension system coupled to said frame;    a steering mechanism pivotably attached to said head tube;    a rear wheel rotatably mounted on said frame;    a front wheel rotatably mounted on said steering mechanism;    a rear wheel drive assembly operating to transmit power from the power transfer mechanism to the rear wheel;    a front wheel drive assembly operating to transmit power to the front wheel, said front wheel drive assembly having at least one adjustable drive component to accommodate movement of the rear suspension system.    
     
     
         2 . The two-wheel drive bicycle of  claim 1 , wherein said at least one adjustable drive component is a universal joint.  
     
     
         3 . The two-wheel drive bicycle according to  claim 1 , wherein said front wheel drive assembly is enclosed within said frame at least from said rear suspension system to said head tube.  
     
     
         4 . The two-wheel drive bicycle according to  claim 1 , wherein said front wheel drive assembly is enclosed within said frame at least from said rear wheel to said rear suspension system.  
     
     
         5 . The two-wheel drive bicycle according to  claim 1 , wherein said front wheel drive assembly is enclosed within said frame from said rear suspension system to said front wheel.  
     
     
         6 . A two-wheel drive bicycle, comprising: 
 a frame, the frame including a head tube;    a power transfer mechanism;    a steering mechanism pivotably attached to said head tube;    a rear wheel rotatably mounted on said frame;    a front wheel rotatably mounted on said steering mechanism;    a rear wheel drive assembly operating to transmit power from said power transfer mechanism to said rear wheel;    a front wheel drive assembly operating to transmit power to said front wheel, wherein at least a portion of said front wheel drive assembly is enclosed within said steering mechanism from said head tube to said front wheel.    
     
     
         7 . The two-wheel drive bicycle of  claim 6 , wherein said front wheel drive assembly is enclosed within said frame and said steering mechanism from said rear wheel to said front wheel.  
     
     
         8 . The two-wheel drive bicycle of  claim 6 , further comprising: 
 a neck tube within the head tube, said neck tube defining a cutout, said cutout accommodating at least a portion of said front wheel drive assembly.    
     
     
         9 . The two-wheel drive bicycle according to  claim 6 , wherein said steering mechanism further includes a shock-absorbing suspension system.  
     
     
         10 . The two-wheel drive bicycle of  claim 6 , wherein said front wheel drive assembly includes at least one ball and spline universal joint.  
     
     
         11 . The two-wheel drive bicycle of  claim 6 , wherein said front wheel drive assembly includes a series of meshing gears located within the steering mechanism.  
     
     
         12 . A front fork assembly for a two-wheel drive two-wheel vehicle which includes a rear wheel drive assembly and a front wheel drive assembly, the front fork assembly comprising: 
 a neck tube;    said neck tube defining a cutout to enable rotation of said neck tube around the front wheel drive assembly and having an upper end and a lower end;    a fork crown attached to the lower end of the neck tube;    a left fork member attached to said fork crown;    a right fork member attached to said fork crown opposite said left fork member;    said left fork member and said right fork member including a dropout at a distal end of each said fork member, said dropout attachable to a front wheel.    
     
     
         13 . The front fork assembly according to  claim 12 , wherein said cutout is defined between an upper neck tube section and a lower neck tube section.  
     
     
         14 . The front fork assembly according to  claim 12 , wherein said fork crown and one of said left fork member and said right fork member enclose said front wheel drive assembly from said neck tube to one of said dropouts.  
     
     
         15 . The front fork assembly according to  claim 12 , further comprising a shock-absorbing suspension system.  
     
     
         16 . A two-wheel drive bicycle, comprising: 
 a power transfer mechanism;    a frame, the frame including a head tube;    a steering mechanism pivotably attached to said head tube;    a rear wheel rotatably mounted on said frame;    a front wheel rotatably mounted on said steering mechanism;    a rear wheel drive assembly operating to transmit power from said power transfer mechanism to said rear wheel;    a front wheel drive assembly operating to transmit power to said front wheel, said front wheel drive assembly having a rider-actuated clutch operating to alternatively engage and disengage said front wheel drive assembly, wherein said clutch is located between a rear hub and a rear dropout of said bicycle.    
     
     
         17 . The two-wheel drive bicycle of  claim 16 , wherein said clutch comprises a pair of interlocking clutch plates.  
     
     
         18 . The two-wheel drive bicycle of  claim 17 , wherein said clutch is cable actuated to move said interlocking clutch plates alternatively into and out of engagement.  
     
     
         19 . The two-wheel drive bicycle of  claim 18 , wherein said interlocking clutch plates comprise at least an inner clutch plate and an outer clutch plate, said cable operating to move said outer clutch plate into and out of engagement with said inner clutch plate, said inner clutch plate being fixed relative to said outer clutch plate.  
     
     
         20 . The two-wheel drive bicycle of  claim 16 , wherein said clutch is attached to a rear drive gear.